Re: [PATCH 3/4] dmaengine: dw-edma: Initialize IRQ data before requesting IRQs

[Frank Li]

On Thu, May 21, 2026 at 11:21:52PM +0900, Koichiro Den wrote:
> dw_edma_irq_request() passes struct dw_edma_irq to request_irq()
> before dw_edma_channel_setup() fills the back pointer. A shared
> interrupt can therefore enter the handler with dw_irq->dw still NULL,
> leading to a NULL pointer dereference.
>
> Set the back pointer before installing each handler.
>
> Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>  drivers/dma/dw-edma/dw-edma-core.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index c2feb3adc79f..d221e3efcb36 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -929,7 +929,6 @@ static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
>  		else
>  			irq->rd_mask |= BIT(chan->id);
>
> -		irq->dw = dw;
>  		memcpy(&chan->msi, &irq->msi, sizeof(chan->msi));
>
>  		dev_vdbg(dev, "MSI:\t\tChannel %s[%u] addr=0x%.8x%.8x, data=0x%.8x\n",
> @@ -1018,6 +1017,7 @@ static int dw_edma_irq_request(struct dw_edma *dw,
>  	if (chip->nr_irqs == 1) {
>  		/* Common IRQ shared among all channels */
>  		irq = chip->ops->irq_vector(dev, 0);
> +		dw->irq[0].dw = dw;
>  		err = request_irq(irq, dw_edma_interrupt_common,
>  				  IRQF_SHARED, dw->name, &dw->irq[0]);
>  		if (err) {
> @@ -1043,6 +1043,7 @@ static int dw_edma_irq_request(struct dw_edma *dw,
>
>  		for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
>  			irq = chip->ops->irq_vector(dev, i);
> +			dw->irq[i].dw = dw;
>  			err = request_irq(irq,
>  					  i < *wr_alloc ?
>  						dw_edma_interrupt_write :
> --
> 2.51.0
>